Battery

Browse 15 battery tools. Opening Battery Calendar Aging Calculator.

Battery PercentageFind remaining charge as a percentage of full capacity.Use this to know exactly how much charge you have left before heading out.
Battery RuntimeEstimate how long a battery lasts at a given power draw.Use this to plan how long your devices will keep running before a recharge.
Battery Charging TimeCalculate how long it takes to charge a battery at a given current.Use this to plan charging ahead so your battery is full when you need it.
Battery Energy CalculatorCalculate battery energy in watt-hours from amp-hours and voltage.Use this to compare batteries by real stored energy, not just amp-hours.
Battery Depth of Discharge CalculatorCalculate how much of a battery's capacity has been used (DoD %).Use this to avoid deep discharges that shorten your battery's life.
Battery Efficiency CalculatorCalculate round-trip efficiency from energy out and energy in.Use this to spot energy losses and see how much charging power goes to waste.
Battery Series & Parallel CalculatorCalculate pack voltage, amp-hours, and watt-hours from series/parallel cell layout.Use this to plan a DIY pack layout and hit your target voltage and capacity.
Battery C-Rate CalculatorFind discharge C-rate and runtime from capacity and load current—updates live.Use this to check your battery can handle the load without stress or damage.
Inverter Loss CalculatorConvert DC input watts to AC output and show power lost as heat in the inverter.Use this to see how much battery energy your inverter wastes as heat.
Inverter Peak Load & Surge CalculatorSum motor running watts and staggered surge demand—get continuous load, peak W, and a recommended pure-sine inverter tier.Use this to buy an inverter that won't trip when your appliances start up.
Inverter Loading CurveEstimate overload shutdown time from nominal power, current load, ambient temperature, and manufacturer overload curves.Use this to know how long you can safely overload your inverter before shutdown.
Home Backup Battery Sizing CalculatorSize a backup battery bank for essential loads, runtime, voltage, and depth of discharge.Use this to size a backup battery that keeps essentials running through an outage.
Battery Voltage Drop CalculatorEstimate DC wire voltage drop and voltage at the load from amps, length, and system voltage.Use this to keep your wiring short and thick enough so devices get full power.
Battery Calendar Aging CalculatorEstimate Li-ion capacity fade from storage temperature, average SOC, and pack age—calendar loss % and remaining SoH.Use this to see how storage habits affect battery health and store packs smarter.
BESS ROI Calculator (Battery Energy Storage System)See if adding battery storage to existing solar pays back from peak vs. off-peak TOU arbitrage—daily savings, payback years, and LCOS.Use this to decide whether adding a home battery will actually pay for itself.

Battery Calendar Aging Calculator

Inputs

Adjust values to update results live

Avg storage temperature (°C)

Ambient where the pack spends most idle hours

Average charge level (% SOC)

Mean state of charge while stored—not peak trips

Remaining capacity (SoH)

Enter storage °C, avg SOC % & age

Calendar capacity loss

Enter values above

Estimated fade rate

Enter values above

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How to use the Battery Calendar Aging Calculator

The Formula

Li-ion cells degrade electrochemically even at zero cycles—SEI growth, electrolyte oxidation, and electrode interactions continue. Heat and high state-of-charge accelerate side reactions. That is calendar aging, distinct from cycle (throughput) aging.

Practical Example

Baseline ~2%/year fade at 25 °C and 50% SOC. Rate scales ~2× per 10 °C above 25 °C and rises sharply when average SOC stays above 80–100%. Planning estimate only—chemistries (LFP vs. NMC) and BMS differ.

About Battery Calendar Aging Calculator

For long idle periods: ~50% SOC, cool and dry (15–25 °C ideal), avoid hot garages at 100%. Re-check SoH before returning backup or seasonal vehicles to service.

Q: Include driving cycles? A: No—this is calendar-only; add cycle wear separately. Q: Can SoH recover? A: No—fade is largely irreversible. Q: Cold storage? A: Slows calendar fade vs. hot, but avoid charging lithium below 0 °C.

Related tools

Battery PercentageFind remaining charge as a percentage of full capacity.Use this to know exactly how much charge you have left before heading out.
Battery Depth of Discharge CalculatorCalculate how much of a battery's capacity has been used (DoD %).Use this to avoid deep discharges that shorten your battery's life.
EV Battery Health & Degradation EstimatorRough state-of-health estimate from age, mileage, and DC fast-charging habits.Use this to check a battery's health before buying or selling a used EV.
Battery RuntimeEstimate how long a battery lasts at a given power draw.Use this to plan how long your devices will keep running before a recharge.

How to use the Battery Calendar Aging Calculator

The Formula

Practical Example

About Battery Calendar Aging Calculator

For long idle periods: ~50% SOC, cool and dry (15–25 °C ideal), avoid hot garages at 100%. Re-check SoH before returning backup or seasonal vehicles to service.

Appliances

Green Home

Backup

EV Charging

Cost

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TOU